ETM cleaning solves idle, MPG problems
About 2 years ago, after a major service (approx 110K) I noticed that the idle was a little odd and seemed to hunt slightly on occasions. Over the last 2 years the problem has got worse to the point where the idle dips to about 500 and jumps up to 1000 very violently and quickly, making the lights flash (rather embarrassing at traffic lights). This happens all the time now, was intermittent. More recently it misfires and belches out smoke when started from cold and won’t accelerate smoothly until warmed up. If I disconnect the battery and leave it for 20 mins the cold start problem goes away for about 5 days and then returns (weird).